From: Asthma in an Urban Population in Portugal: A prevalence study
Year
Study
Prevalence %
Method
1992
Nunes et al [26]
5.5
Questionnaire
2005
Branco et al [31]
8.6
Self-report/Interview
2006
Portuguese National Health Survey [40]
2009
Correia-de-Sousa et al
10.2
Questionnaire, self-report of symptoms